Endocrine Disrupting Chemicals in Water, Sediments and Fish Observed in Urban Tributaries of the Freshwater Tidal Potomac River: Occurrence, Bioaccumulation and Tissue Distribution.

摘要

The goal of the present study was to assess the ecological impacts of legacy and contemporary endocrine disrupting chemicals (EDCs) in the upper tidal Potomac River associated with WWTP discharge. Legacy EDCs includes polychlorinated biphenyls (PCBs) and the present study quantified total-PCBs and dioxin like PCBs (dl-PCBs), which are the more toxic PCB congeners, in bed sediments and biota from Hunting Creek and Gunston cove to evaluate the significance of dl-PCBs in the upper Potomac River.;Dl-PCBs were consistently detected in sediments and fish from both Gunston Cove and Hunting Creek. PCB 118 and 123 had the highest concentration (0.56 +/- 0.03 ng/g dwt) followed by PCB105 (0.28 +/- 0.01 ng/g dwt) in Gunston Cove sediment while PCB105 and 118 dominated the Hunting Creek sediment with concentrations of 1.66 +/- 0.71 and 1.31 +/- 0.57 (ng/g dwt) respectively. The highest fish dl-PCB congener detection belonged to PCB118 and 123 (62.9 +/- 25.3 ng/g lipid) followed by PCB105 (29.5 +/- 9.83 ng/g lipid), reflecting the sediments profile observed in the Gunston Cove. PCB118 (31.3 +/- 27.8 ng/g lipid) was the dominant dl-PCB, followed by PCB105 (13.6 +/- 6.70 ng/g lipid) in Hunting Creek fish, reflecting the Hunting Creek sediment profile as well. Statistical analysis indicated geospatial differences among the sites as well as differences among fish species.;This study also assessed the ecological impacts of contemporary endocrine disruptor chemicals (EDCs) in Hunting Creek, Accotink Creek and Pohick Creek associated with WWTP discharge. Triclosan and dextromethorphan were the two analytes detected in water, sediments and fish samples. Triclosan (TCS) is a broad-spectrum antibacterial mostly used in soap and dextromethorphan (DXM) is an antitussive agent readily available in over-the-counter (OTC) drugs. Tissue distribution analysis for DXM and TCS in fish revealed selective bioaccumulation of the two analytes in skin, stomach and gonads, without any correlation to the lipid content of the perspective tissues.;Mean concentrations of triclosan observed in Hunting Creek water, sediments and whole fish (banded killifish and white perch) were 15.5 +/- 3.71 ng/L, 72.5 +/- 9.41 ng/g dwt, 72.2 +/- 4.56, and 81.8 +/- 5.84 ng/g wwt, respectively. Mean observed dextromethorphan concentrations in Hunting Creek water, sediments and whole fish (banded killifish and white perch) were 74.9 +/- 11.8 ng/L, 103 +/- 84.2 ng/g dwt, 470 +/- 7.06, and 304 +/- 43.3 ng/g wwt, respectively.;Mean concentration of dextromethorphan in Accotink Creek whole fish, alewife and gizzard shad, and sediments were 45.3 +/- 9.12 ng/g wwt, 101 +/- 11.1 ng/g wwt and 91.1 +/- 3.52 ng/d dwt, respectively. Triclosan was not detected in Accotink sediments and mean TCS concentration in alewife and gizzard shad whole fish homogenate were 76.1 +/- 9.13 ng/g wwt and 45.5 +/- 7.04 ng/g wwt, respectively.;Mean concentration of dextromethorphan in Pohick Creek whole fish alewife and gizzard shad and sediments were 49.1 +/- 9.68 ng/g wwt, 134 +/- 11.8 ng/g wwt, and 233 +/- 48.9 ng/g dwt, respectively. Triclosan was not detected in Pohick Creek sediments and whole fish homogenate for alewife and gizzard shad were 47.9 +/- 6.89 ng/g wwt and 51.7 +/- 5.32 ng/g wwt, respectively.;The greatest DXM concentration was observed in alewife stomach (2000 +/- 156 ng/g wwt) and lowest in alewife muscle (74.3.5 +/- 5.34 ng/g wwt). The greatest TCS concentration was observed in gizzard shad testes (274 +/- 60.5 ng/g wwt) and lowest concentration was observed in alewife muscle (192 +/- 87.4 ng/g wwt).;Triclosan and dextromethorphan gonad concentrations ranged from 102 to 274 ng/g wwt (for TCS) and 265 to 1,273 ng/g wwt (for DXM) suggesting parental transfer to offspring is possible, warranting further research and analysis.;The consistent detection of TCS and DXM across water, sediment and fish species warrants further research considering the recent well documented increase in use of TCS and reported risks to the aquatic environment and fish. DXM is one of the top five over-the-counter (OTC) drugs being abused in many countries, and would manifest psychiatric symptoms induced by chronic abuse.